Purpose: It is well known that hepatocellular carcinoma (HCC) is an arginine auxotroph due to argininosuccinate synthetase I deficiency. This study's purpose was to evaluate the effects of pegylated arginine deiminase (ADI) in terms of toxicity, tumor response, α-fetoprotein (AFP) levels, and serum arginine levels. Patients and Methods: Eighty patients were randomly assigned to receive either 80 IU/m2 or 160 IU/m2 of ADI weekly for up to 6 months. Adverse events, serum arginine, AFP levels, and antibody production against ADI were measured on a regular basis. In addition, disease response and time to progression according to the Response Evaluation Criteria in Solid Tumors (RECIST) and survival rates were evaluated. Results: Four patients were excluded from the survival analysis because they developed exclusion criteria after randomization, but before first treatment. The number of patients in the two cohorts were similar (n = 37 in the low-dose cohort, n = 39 in the high-dose cohort). Mean (±SE) survival for all subjects was 15.8 months (474 days ± 39 days) from time of diagnosis of unresectable disease. Arginine levels remained below baseline for 50 days while antibodies against ADI reached a plateau at approximately the same time. There were no deaths attributed to ADI treatment. Only two patients were withdrawn for immunogenic-related adverse events. Grade 2, 3, or 4 toxicities were recorded in 92, 19, and 0 patients, respectively. Conclusion: Pegylated ADI is a promising drug that capitalizes on a significant enzymatic deficiency in HCC. It is safe, well tolerated, and may benefit patients with unresectable HCC.
Although hepatic metastasectomy is well established for colorectal and neuroendocrine cancer, the approach to hepatic metastases from other sites is not well defined. We sought to examine the management of noncolorectal non-neuroendocrine liver metastases. A retrospective review from 4 major liver centers identified patients who underwent liver resection for noncolorectal non-neuroendocrine metastases between 1990 and 2009. The Kaplan-Meier method was used to analyze survival, and Cox regression models were used to examine prognostic variables. There were 420 patients available for analysis. Breast cancer (n = 115; 27%) was the most common primary malignancy, followed by sarcoma (n = 98; 23%), and genitourinary cancers (n = 92; 22%). Crude postoperative morbidity and mortality rates were 20% and 2%, respectively. Overall median survival was 49 months, and 1, 3, and 5-year Kaplan-Meier survival rates were 73%, 50%, and 31%. Survival was not significantly different between the various primary tumor types. Recurrent disease was found after hepatectomy in 66% of patients. In multivariable models, lymphovascular invasion (p = 0.05) and metastases ≥5 cm (p = 0.04) were independent predictors of poorer survival. Median survival was shorter for resections performed between 1990 and 1999 (n = 101, 32 months) when compared with resections between 2000 and 2009 (n = 319, 66 months; p = 0.003). Hepatic metastasectomy for noncolorectal non-neuroendocrine cancers is safe and feasible in selected patients. Lymphovascular invasion and metastases ≥5 cm were found to be associated with poorer survival. Patients undergoing metastasectomy in more recent years appear to be surviving longer, however, the reasons for this are not conclusively determined.